Method of aligning one dimensional or two dimensional codes to printer pixels

Abstract

A printer processor in which accuracy of a printed image is essential. The printer processor receives exact pixel characteristics from a target printer, and instructs the target printer to exactly reproduce the desired image after eliminating any distortions introduced by scaling or rotational factors.

What is claimed is: 
     
       1. A printer processor implemented method for printing machine-readable code images on a selected printer having reproduction characteristics known and available, each machine-readable code image being defined by a code bitmap and having rectilinear areal geometric characteristics, the method including the steps of: introducing a code bitmap of a machine-readable code image to be printed into a printer output image bitmap by means of software which imposes a risk of inducing image bitmap distortion;   obtaining for the printer processor the known reproduction characteristics of said selected printer;   analyzing, by said printer processor, physical pixel array characteristics of said printer based on said known reproduction characteristics;   transforming the code bitmap of the machine-readable code image in the printer output image bitmap to resize and rotate the code image as required to align essentially exactly rectilinear areal geometric characteristics of the code image with integer multiples of said printer's physical pixel array characteristics; and   printing on the selected printer the code image defined by the transformed code bitmap in the printer output image bitmap.   
     
     
       2. A method according to claim 1, further comprising the step of: after the step of analyzing physical pixel array characteristics of the printer and before printing the code image on the printer, transforming the code bitmap of the machine-readable code image in the printer output image bitmap to shear correct the code image as required to align essentially exactly rectilinear areal geometric characteristics of the code image with integer multiples of said printer's physical pixel array characteristics.   
     
     
       3. A printer processor implemented method for printing machine-readable code images on a selected printer having reproduction characteristics known and available, each machine-readable code image being defined by a code bitmap and having rectilinear areal geometric characteristics, the method including the steps of: introducing a code bitmap of a machine-readable code image to be printed into a printer output image bitmap by means of software which imposes a risk of inducing image bitmap distortion;   obtaining for the printer processor the known reproduction characteristics of said selected printer;   analyzing, by said printer processor, physical pixel array characteristics of said printer based on said known reproduction characteristics;   transforming the code bitmap of the machine-readable code image in the printer output image bitmap to resize and reposition the code image as required to align essentially exactly rectilinear areal geometric characteristics of the code image with integer multiples of said printer's physical pixel array characteristics; and   printing on the selected printer the code image defined by the transformed code bitmap in the printer output image bitmap.   
     
     
       4. A method according to claim 3, further comprising the step of: after the step of analyzing physical pixel array characteristics of the printer and before printing the code image on the printer, transforming the code bitmap of the machine-readable code image in the printer output image bitmap to rotate the code image as required to align essentially exactly rectilinear areal geometric characteristics of the code image with said printer's pixel array characteristics.   
     
     
       5. A method according to claim 3, further comprising the step of: after the step of analyzing physical pixel array characteristics of the printer and before printing the code image on the printer, transforming the code bitmap of the machine-readable code image in the printer output image bitmap to shear correct the code image as required to align essentially exactly rectilinear areal geometric characteristics of the code image with integer multiples of said printer's physical pixel array characteristics.   
     
     
       6. A printer processor implemented method for printing machine-readable code images on a selected printer having reproduction characteristics known and available, each machine-readable code image being defined by a code bitmap and having rectilinear areal geometric characteristics, the method including the steps of: introducing a code bitmap of a machine-readable code image to be printed into a printer output image bitmap by means of software which imposes a risk of inducing image bitmap distortion;   obtaining for the printer processor the known reproduction characteristics of said selected printer;   analyzing, by said printer processor, physical pixel array characteristics of said printer based on said known reproduction characteristics;   measuring a rotational difference between a pixel array defined by the code bitmap of the machine-readable code image in the printer output image bitmap and said printer's physical pixel array characteristics;   comparing the magnitude of said rotational difference with zero and with a predetermined maximum acceptable rotational difference value; and:   (i) if the magnitude of the rotational difference is greater than zero and does not exceed said maximum acceptable rotational difference value, transforming the code bitmap of the machine-readable code image in the printer output image bitmap to essentially eliminate said rotational difference to align essentially exactly rectilinear areal geometric characteristics of the code image with said printer's physical pixel array characteristics, and   printing on the selected printer the code image defined by the transformed code bitmap in the printer output image bitmap; or   (ii) if the magnitude of said rotational difference exceeds said maximum acceptable rotational difference value, printing an error-indicating communication.   
     
     
       7. A method according to claim 6 in which the error-indicating communication is an error-indicating graphics image. 
     
     
       8. A printer processor implemented method for printing machine-readable code images on a selected printer having reproduction characteristics known and available, each machine-readable code image being defined by a code bitmap and having rectilinear areal geometric characteristics, the method including the steps of: introducing a code bitmap of a machine-readable code image to be printed into a printer output image bitmap by means of software which imposes a risk of inducing image bitmap distortion;   obtaining for the printer processor the known reproduction characteristics of said selected printer;   analyzing, by said printer processor, physical pixel array characteristics of said printer based on said known reproduction characteristics;   measuring shear distortion between the pixel array defined by the code bitmap of the machine-readable code image in the printer output image bitmap and said printer's physical pixel array characteristics to determine a shear error amount;   comparing the magnitude of said shear error amount with zero and with a predetermined maximum acceptable shear error amount value; and,   (i) if the magnitude of the shear error amount is greater than zero and does not exceed said maximum acceptable shear error amount value, transforming the code bitmap of the machine-readable code image in the printer output image bitmap to essentially eliminate said shear distortion to align essentially exactly rectilinear areal geometric characteristics of the code image with said printer's pixel array characteristics, and   printing on the selected printer the code image defined by the transformed code bitmap in the printer output image bitmap; or   (ii) if the magnitude of said shear error amount exceeds said maximum acceptable shear error amount value, printing an error-indicating communication.   
     
     
       9. A method according to claim 8 in which the error-indicating communication is an error-indicating graphics image.